Researchers from Brown University in Rhode Island have developed an algorithm that allows standard digital cameras, such as in smartphones, to be used as high-quality 3-D scanners. The typical technique used by commercially available 3-D scanners is image capture through structure light. A projector casts a series of light patterns on an object, while a camera captures images of the object. When patterns deform from surface, the scanner can calculate the depth and surface configurations of the objects in the scene, but this require precise synchronization. Without synchronization the projector could switch from one pattern to the next while the image is in the process of being exposed, and most digital cameras use a rolling shutter mechanism. The researchers developed an algorithm that enables the structured light technique to be done without synchronization between projector and camera. The camera just needs to be able to capture uncompressed images in burst mode. From that the algorithm calibrates the timing of the image sequence using the binary information embedded in the projected pattern. Then it goes through the pixels to assemble a new sequence of images that captures each pattern in its entirety. Once assembled, a standard structured light 3-D reconstruction algorithm can be used to create an image.
Source: Brown University
